Further details have emerged of Microsoft's plan to drive sales of Windows 7 by offering big discounts to users who pre-order the software online. Windows 7 will go on general sale in the UK, the US and other territories on 22 October.

After the perceived failure of Windows Vista, Microsoft has resisted the temptation to slash the headline price of its successor: Windows 7. But bargain-hungry PC users who want to get hold of the upcoming OS can make massive savings by pre-ordering online.

Microsoft last month revealed how much it will charge for its next PC operating system, Windows 7. Windows 7 Home Premium Edition will cost £149, while the Professional version will be £219 and the Ultimate Edition £229.

The Home Edition of Windows 7 is £20 cheaper than the equivalent version of Windows Vista. The Professional and Ultimate versions cost the same as their Vista equivalents.

But although Microsoft has avoided devaluing the Windows brand with its official pricing, there are bargains to be had. When announcing the price of Windows 7 in June, Microsoft said it would offer EU customers Windows 7 Home Premium for only £79 if bought between the launch date of 22 October and the end of the year.

Microsoft also said it would offer significant discounts on a limited number of Windows 7 licences pre-ordered in a limited period over the summer.

From the 15 July to the 9 August, for instance, UK retailers such as Micro Anvika are running the introductory offer on pre-orders of Windows 7. PC users can buy a Windows 7 Home Premium licence for £49 - a saving of £100. Alternatively Windows 7 Pro will retail for just £99: £120 less than Microsoft's suggested retail price (SRP).